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This paper proposes a control strategy for combining Variable Speed Limits (VSL) and Ramp Metering (RM) to maximize the flow of a recurrent bottleneck which can be modeled as a lane reduction. The control strategy can be simply described as: (a) Assuming a known ramp metering rate for each onramp; (b) using Finite Time Horizon Model Predictive Control to(More)
With the dramatic development of image processing technology, a growing number of traffic flow detection and analyses have been conducted by using video data. Time to collision (TTC) and postencroachment time (PET) are two major parameters used to indicate the severity of a potential collision and to capture an imminent vehicular accident. However,(More)
The METANET model, deduced based on equilibrium state assumption, provides a candidate model for freeway traffic control design since it has both speed and density dynamics, but the previous work parameterized the speed control variable to be highly nonlinear, which caused difficulty in control design and implementation. Besides, the model could not catch(More)
Accurate queue estimation of traffic congestion at recurrent freeway bottlenecks is an important part of developing effective traffic control strategies. Two traffic flow analytical techniques are always employed in studying queuing processes: shockwave analysis and input-output analysis. These two techniques have been taken as separate tools for estimating(More)
In this paper various theories on traffic jams and stop-and-go wave modeling were reviewed and discussed. These include traditional microscopic car-following model, asymmetric traffic theory, first-order and second-order macroscopic models, traffic disturbance model, phase transition model as well as macroscopic simulation. The mechanism of stop-and-go(More)
Freeway work zone is considered as a potentially hazardous zone, which asks for special speed restriction to provide a relatively safe environment for road users and workers. However, the efficacy of speed limit reduction to bring about significant change in collective speed behavior on construction sites is yet to be determined. In this regard, this study(More)
Estimating arterial link travel times and traffic delays using vehicular positioning data, such as automatic vehicle location (AVL) data, is still a challenging subject. The difficulties exist in allocating the travel time between two consecutive AVL reports of a vehicle to each traversed link, especially when the data sampling frequency is low, and(More)
Freeway congestion is highly recognized as a worldwide traffic problem since traffic demand has grown steadily over the past decades. Active traffic and demand management (ATDM) methods, including Ramp Metering (RM), Variable Speed Limit (VSL), and Route Guidance (RG), can help delay or even avoid congestion. Currently, those measures have become predictive(More)
Traffic state estimation is important for active traffic planning, management, and control. By utilizing traffic status over time and space, a key theoretical analysis tool, i.e., shockwave theory, can be adopted as efficient tools to solve bottleneck or congestion problems. Two methods, who are fixed point observations and mobile probe vehicle(More)